Thinking about putting up a dipole in attic

[ElectronTubesRule]

Ok, I am not currently on the air. I am currently renting from relatives and just moved in a few weeks back. The second floor has doors that lead directly to attic space on each side of the finished up stairs rooms! I am on a tight budget so that is why I was thinking dipole. I was going to set it up with Balun so no need for tuner since I have not gotten around to building one yet. So I will likely go with single band dipoles initially because they are almost idiot proof.

So my question is this I have never used a dipole as a main antenna I have used them them in field environment and that is it. So I have no idea what to expect in terms of living with a dipole day in and day out. Since it will be in the attic protected from the elements and wind and will not be saging it should be good.

How does a dipole behave compared to a vertical Omni-directional antenna. Will the radiation angle allow for any local talking? How big of a pain is it being horizontal polarized when most of the traffic will be verticly polarized? I always had omi-verticles or beams with horz. and vert. polarity this is the first time I will have ever used a dipole as a base station antenna.

The attic space I have is only about 3 foot high but it is easily 40 feet long. So I was just going to lay it out flat across the truss's. I have a TV tower I can use when I have the money for a proper antenna but right now I am focusing on parts for my RF amplifier and am on a very very low budget!

Oh the truss base that I planed on stretching the wire across is aprox. 20 feet about the ground. My bedroom is on the second floor and my kids are on the first floor so I would have easy access to the antenna.

I also thought about building a dipole out of large copper or aluminum poles and use a gama match for tuning swr. It would also be in the attic so weather is not much of a factor.

Their is no way to mount something like a A-99 or Imax 2000 both of those would have to lie flat in the attic plus since those are 11meter antena's I would need a tuner down the road to use them on anything else.

Oh and for now since I have not taken my test yet I am just going to be listening in on 10,12m and maybe talking on 11 on SSB if their is anything worth listening too that is not full of swearing and trash talk!

So any of you guys live with a dipole as your primary antenna for any length of time? Any cautions or anything I should know about? I have never known anyone that has lived with a dipole. Generally dipoles where for field use only. I do understand that most verticles are not much more then end fed dipoles or some modification of that design.

Thanks by the way. I know sounds like a stupid question but like I said I do not know anyone in real life that has used a dipole for any length of time especially not at their home! Most of my friends are older then me and have deep pockets and huge antenna's!!!LOL

 

[Beetle]

Put it up and get on the air. There's no need for a committee to figure things out. If there's no pipes, vent ducting or other significant metallic structures in the attic, put the dipole up, adjust it and use it. You'll learn a lot more by doing that than reading others' stories.

 

[Needle Bender]

think about a full wave 36 foot loop even if it is only a couple feet high. you can use a 1/4 wave of rg-11 to match it. should offer some gain and cause less tvi

 

[wavrider]

Where to begin?????

First and foremost your antenna is 95% of your station.

Get the best antenna you can afford, get it up in the air as high as you can get it within reason, (DOC will tell you a 1/4 mile or so is good)

Forget about that amplifier as right now the solar cycle is on the upswing, contacts are being made world wide using 5 watts output on 10 meters and 11 meters is the same way.

I suggest studying homebrew yagi's, quads etc etc, you can get all the construction material from Home Depot or at Slowe's, EMT conduit is inexpensive and works for building antenna, either yagi's or verticals.

I used it to build a four element 10 meter monobander , a four element 6 meter mono bander and also my 5/8 wl 6 meter vertical. for less than $25 dollars and a little bit of time you can have a three or four element yagi in the air. That will be the same as have a few hundred watts of amplifier, the plus is you will be able to receive better with the yagi, the amplifier will not help on the receive.

Get an antenna up and start making some contacts.

Tips and tricks on how to build your own CB Antennas.

The 5/8 wl vertical in this article is easy to build, can use EMT conduit and from experience it will work and work good.

 

[74IN]

Why does the use of a balun make you not need a tuner?

If the dipole is made correctly, no need for a tuner or a balun.

Amateur Dipole Antenna Calculator

 

[wavrider]

A balun or the old ugly choke coax wrapped type will help eliminate CMC on the feed line.

Since the install will be in an attic, every little bit of precaution to eliminate CMC and TVI issues will help.

 

[W5LZ]

Just a few things to keep in mind.
Start with an antenna that's a bit too long, then 'trim' it to get it down to the right length. Lot's easier than adding to a too short antenna.
The difference in polarization means that 'local' vertically polarized signals are going to be less than they could be. If you could mount that dipole vertically, that's not a problem. With the space you have to work with, that vertical thingy just isn't going to 'fly'. Use what you got.
A dipole can be bent to some extent with no real problem. It doesn't have to be perfectly 'straight' by any means.
A balun just isn't absolutely necessary for HF antennas. You'll find more without baluns than you will with baluns, and the users are just as happy.
Another factor with an indoor antenna, no matter what kind they are, is that it won't work as well as it would outside. So, figure on it not being the 'best' performer. That certainly doesn't mean it has to be terrible, but it's at a disadvantage to start with, the signals have to go through whatever the roof/walls are made from instead of just plain air.
The biggest 'problem' you will have in your situation will be polarity. Not much you can do about that, so do what you can with what you got.
- 'Doc

Don't worry about 'grounding', a dipole doesn't need it to work correctly. And if it get's struck by lightning, the antenna is probably the last thing I'd be worried bout, you know? And no, they don't 'attract' lightning.

 

[wavrider]

Just A balun just isn't absolutely necessary for HF antennas. You'll find more without baluns than you will with baluns, and the users are just as happy.

Their neighbors computer speakers as well as other ops on the band will not be just as happy.

Baluns, current types distribute equal amount of current into each leg of the dipole, isolating the feed line from the antenna, making a cleaner more symmetrical radiated signal, this equals a more efficient antenna.

Without a balun or choke at the feed point the feed line will become part of the antenna. It will radiate. In some cases this may be a good thing, IE the statement "They are just as happy without one". The radiating signal from the feed line is in the vertical plane, thus giving some good DX.

This has been discussed and debated till it got boring to debate.
Some ops say not to use one, they probaly do not look at any EZNEC models of dipoles with no baluns.

 

[W5LZ]

The majority of RF that causes problems comes from the antenna it's self, not from the feed line. A balun is not a guaranty that the feed line won't radiate, that little gem is a myth. A balun can certainly reduce that feed line's radiation, but don't count on it 'curing' an RFI problem.
- 'Doc

 

[ElectronTubesRule]

I was not trying to make this a committee decision....LOL Just thought I would ask if their was anything I was over looking or needed to know before I dived in head first! LOL n my youth I was known to leap with out first looking now that I am older and sometimes wiser I figured what the heck might as well ask?!?! I was particularly interested in how bad local reception would be. Seeing how I have not been on the radio for about 8-10 years other then on rare long distance road trips on the interstate. 4 years a go going from Michigan to Florida to help relocate a friend from flight school it saved me from 2 speed traps and also bad directions from the GPS unit. Have not been on since. LOL So I was just wondering how bad local communications would be due to the radiation angle of a horizontal dipole. So I was not trying to put it to the comettee.....LOL Having survived working for GM with out developing an ucler or anything worse I am not a fan of meeting for the sake of meeting....LOL

 

[ElectronTubesRule]

Yes, I have other houses all around me all of them have satalite TV or Digital Broadcast TV. Then you have all the computer's in my area. My TV is a Plasma big screen lets hope it does not cause havoc in the HF spectrum!!!LOL So the Balun is being used to isolate my feed line which is coax not ladder line and to balance the signal to the feed line radiating elements. I am hoping it will keep me out of the neighbors TV's,Computer's Wireless Telephones etc........I try to be a kind neighbor.

Seeing how I am not going to be running any power and will be using basically a properly aligned single final CB it should not be too bad. Anything that is not right only get's worse the more power you pump out of it. I used to live on SSB so that is more then likely will I will stay.

Anyone that thinks the Old Grants and Combra 148's rock would love the unit I am talking on. It has am audio and SSB audio that is out of this world when set up right. Palomar 500 and SBE 500 40 Channel SSB rigs that are rock solid on SSB and have huge audio. The only problem being if you blow the audio ic your SOS as no one makes a replacement for them. Anyone that hears me on the air with crappy stock mic always wants to buy them off me. They are stock too no modifications of any kind not even the channel mod. wattage is standard 1969 transistor output so nothing big. The audio and freq. stability is what makes both of these units so killer.